Here's a quick run down. I have a 98 gst that I converted awd and then recently just finished installing a ford 8.8 keeping it awd. I bought conversion fittings to mate my exsiting brake lines to the ford calipers and made ss lines. I also have a cnc staging brake that installed. I bled the system numerous times and the pedal still has a spongy feeling.

Things I have replaced are:
-2g brake master cylinder
-3g brake master cylinder
-new proportion valve

I have no leaks, calipers are good so i have no idea what else to try. My concern is that, since the ford calipers are bigger maybe the master is having a hard time getting fluid in the rear calipers, therefore causing the pedal to have the spongy feeling. When I drive the car and push the brake pedal, the pedal travels almost to the floor before it starts to stop.

any help would be great, thanks

Some thing easily over looked is the orientation of the bleeder screws. Make sure they are on the top of the caliper not the bottom.

Cardone® W0133-1822918 - Ford Explorer 2001 Remanufactured Brake Caliper

this is the caliper. the bleeder screw is on the bottom when its bolted on

Then you have them on the wrong side...This by its self will cause your spongy pedal as there is still air trapped in the calipers.

Okay thanks, I will try swaping them tomorrow and will report back with results

bench bleeding master cylinder also?

Thanks, but I did bench bleed the master befor I put it on